052试题 49 - thread alert

49. View the Exhibit to examine the output of the DBA_OUTSTANDING_ALERTS view.

After 30 minutes, you executed the following command:
SQL> SELECT reason,metric_value FROM dba_outstanding_alerts;
REASON METRIC_VALUE
------------------------------ ------------
Tablespace [TEST] is [28 perce 28.125nt] full
What could be the reason for the elimination of the other rows in the output?
A.An Automatic Workload Repository snapshot has been taken recently.
B.The non-threshold-based alerts are transferred to DBA_ALERT_HISTORY.
C.The threshold alerts conditions are cleared and the alerts are transferred to DBA_ALERT_HISTORY.
D.The threshold alerts related to database metrics are permanently stored in DBA_ALERT_HISTORY but
not the threshold alerts related to instance metrics.
 

参考答案 C

解析

题目意思问，半个小时前后的记录。有些记录没有了。为什么？

原因，thread alert 记录被保存到了dba_alert_history中了。

参考文档：

https://docs.oracle.com/cd/E11882_01/server.112/e25494/monitoring.htm#ADMIN11253

Server-Generated Alerts Data Dictionary Views

The following data dictionary views provide information about server-generated alerts.